Heretofore, sesquiterpene esters and essential oils have been obtained from guayule-like resins.
U.S. Pat. No. 2,549,763 to Banigan, et al, relates to a process for isolating betaine from guayule extract. The aqueous non-resinous extract phase was isolated, diluted with alcohol, and treated with phosphoric acid. No treatment or extraction with regard to the guayule resin was employeed.
U.S. Pat. No. 2,572,046 to Meeks, et al, relates to a process for isolating parthenyl cinnamate and essential oils from guayule resin by mixing a water-miscible, organic solvent solution of the guayule resin with a hydrocarbon in which the parthenyl cinnamate is more soluble than in the organic solvent and separating the hydrocarbon containing the parthenyl cinnamate from the mixture.
U.S. Pat. No. 4,542,191 to Kay, et al, relates to tackifying agents for rubber by chemically treating a guayule resin fraction with such compounds such as formaldehyde, phenol/formaldehyde, urea formaldehyde, and the like. The guayule resin can be extracted with polar solvents.
U.S. Pat. No. 4,616,068 to Schloman and Davis relates to improving physical properties of rubber compositions by chemically treating guayule-type resins with a polyamine.
U.S. Pat. No. 4,622,365 to Schloman and Davis relates to improving physical properties of rubber compositions by chemically treating guayule-type resins with an amine terminated polyether.
The article "Guayule Byproduct Evaluation: Extract Characterization", by Schloman, et al, J. Agric. Food Chem., 1983, 31(4), 873-876, relates to composition profiles of water and acetone extracts of guayule woody tissue.